Field of the Invention
The present invention is related to the field of microprocessor controlled relays for motors and compressors, and more particularly, to a microprocessor controlled vehicle relay for HVAC systems installed in buses and other high occupancy vehicles that can be configured in different ways to provide a number of operational functions for improved safety as well as greater motor and/or compressor longevity.
Description of the Related Art
Climate control systems such as air conditioning systems in vehicles draw significant current upon initial start up. In large high occupancy vehicles such as buses which require heavy duty systems to provide the necessary cooling, the initial in-rush of current to the DC fan motor upon start-up of the air conditioning system can be on the order of 60 amps or more. This large inrush current could create a safety hazard under certain circumstances and also requires that the system include a large fuse able to withstand the surge in current. Should the motor fail, the high amount of current can create a dangerous condition and may overheat the fan motor to the point of catastrophic failure.
Accordingly, a need exists for a vehicle relay that reduces the inrush current to the DC fan motor upon climate control system start-up in buses and other high occupancy commercial vehicles to improve safety while also eliminating the need for large fuses and increasing motor longevity.
In addition, it would be advantageous to have a relay for a commercial high occupancy vehicle that is installed and able to protect against HVAC compressor overspeed, undervoltage to the compressor clutch in an HVAC system, and excessive cycling of the HVAC system compressor for extended motor life.